Longitudinal psychological samples skew toward stable, urban, educated people

Evidence

These 86 alumni cannot be considered representative of any larger group, not even of my university’s graduates. They went to school for a long time, they allowed the alumni office to keep in touch with them, and they answered my request. Most of them still lived in Winnipeg, and all but 8 still lived in Canada. As a group they are Canadian urban professionals, married with children. — Bob Altemeyer, The Authoritarian Specter, 1125